Alloy



Patented July ZO, 1926.

UNITED" STATES PATENT l OFFICE.

HAROLD G. ,L'WEIDENTEAL, OF CLEVELAND, OHIO, ASSIGNOB- TO THE JAMES H. HEBRON COMPANY; 01 CLEVELAND, OHIO, A CORPORATION OF OHIO.

ALLOY.

' Io Drawing.

This invention relates to alloys and has for its object the provision of an improved metallic composition, devised primarily for the purpose of making die-blocks and like tools for the working of hot metals, but of great value for many other purposes such as light armor, armor plate, gun liners, frogs and crossings of railways, dipper teeth, gas-engine valves and in many other places where a hard and durable alloy is required which will stand either high temperature or severe mechanical wear. Further objects of the invention are the provision of a composition of this nature which shall be made of comparatively inexpensive materials, shall be either oil hardening or air hardeninp' and shall be little if any injured by over eating. It is also an object of the invention to produce a metal which can be read ily forged, and easily welded, and. conveniently machined when annealed or softened.

My improved alloy is most conveniently made by adding to steel of the proper carhon-content a predetermined amount of silicon together with the proper amount of chromium, preferably accompanied by a small amount of some scaven 'ng agent such as uranium, vanadium, mo ybdenum, zirconium, or titanium. A specimen composition which I have found to give extremely satisfactory results isas follows:

Chromium, 3% to 6%, silicon 1% to 2 carbon .30% to 1.00%, uranium (or equivalent) .10% to 30%, phosphorous, sulphur, manganese as in normal steel specifications, iron by difference to make 100%. I

The effect of the silicon is to afford a very high coeflicient of elasticity, combined with great density, but normally accompanied by a rather abrupt elastic limit, at least for dynamic force. The effect of the chromium is to render the alloy air hardening when used in conjunction with the silicon. The hardness of the alloy will depend to a very great extent upon the carbon content, running from quite soft (where an-' nealed) .at .30 carbon up to a super-hardness at 1.00 carbon (the usual practlcal limit bein about .60%).

I have found uranium. to produce a more satisfactory action in this alloy than any of the other substitutes therefor which I have,

named, yet any of the equivalents mentioned serve in my opinion to produce an alloy which is better than anything heretofore Application filed April 3, 1919. Serial No. 287,284.

known. I do not restrict myself to the quantities of these substances hereinbefore mentioned, since more may be used if desired, but the benefit derived by larger quantities is rather doubtful;

The proportion of chromium must not be allowed to run much if any above 6% and less than 5% is safer because of a brittle and hot-short condition which is produced. Good results can, however, be obtained down to about 2% of these metals but the air hard- I ening properties are not so pronounced.v

- ance of the uranium as a'result of scavenging action. This, as in the case of all metal working, depends largely upon the skill of the melter. One reason why uranium is decess does not injure the resulting alloy as is the case with some scavenging elements.

- sirable in thiscon'nection is that a. slight ex- However I have indicated certain equiva- 1 lent-s which may be substituted therefor and do not limit myself to the use of uranium.

' Little total change is produced in the r0 portions of chromium, silicon, or iron. arbon tends to rise but must be kept 'below 1.00% and preferably below .60%. Accordingly the ultimate composition of the alloy is: Chromium 3% to 6%, silicon 1% to 2 uranium and equivalents substantially disappeared, phosphorous, sulphur, manganese as at first, iron to make 100 By the term alloy I mean any metallic composition of practical value, containing a plurality of metallic ingredients, regardlessas to the particular internal structure exhibited thereby.

A casting made from my improved alloy exhibits great toughness, rigidity, strength, and permanence, and possesses an extremely fine and regular crystal formation, together with a tough and silky fracture. This crystal arrangementis not impaired either by prolonged overheating or by sudden chill-- forging can be readil ing. At points above a red heat the alloy can be forged with ease and accuracy and indicates no tendency towards a hot shortness at any temperature. long slow cooling, either the casting or machined, and by merely reheating and a lowing to cool in the open air will regain such a degree of hard-- ness as is desired for any of the uses above mentioned. This hardness may be regulated by the rate of cooling or may be tempered after sudden cooling (as in oil) by heating to any point short of its temperature of recalescence.

This tempering, however, is peculiar in that heating to 1400 Fah. toughens the al-' loy but does not entirely withdraw its hard ness, leaving it hard enough to withstand hot-metal working. Heating does not warp A machined or finished article can be hardened locally merely byheating very hot at or change the dimensions of a machined article appreciably and produces only an immaterial amount of scale even at 2000 Fah.

the desired point and allowingto cool.

If annealed .by

I have found this alloy a perfect substitute for 10% tungsten steel (which also normally carries 4% of chromium and 1% vanadium). in all uses which have so far come to my attention, and can'be made at much smaller cost. This alloy can be made by the electric open hearth, or crucible process and by any of theknown processes of making steel.

Having thus described my invention what I claim is 1. An alloy consisting essentially of iron containing from about three to about six per cent of chromium and between about one and two and one-half per cent of silicon together with less than one per cent of carbon.

2. A turnace charge of the nature described containing essentially: Silicon 1% to fi carbon .30% to 1.00%; chromium 3% to 6%, metallic scavenging element .1% to 5% having the herein essential qualities of uranium, iron to make In testimony whereof, I her'eunto aflix my signature.

HAROLD G. WEIDENTHAL. 

